2004-11-14 04:00:00 PDT Toronto -- Usually, the actors I meet turn out to be Lilliputians compared with their screen image. But Liam Neeson is even bigger than he appears on film. He's 6 feet 4 with a large, solid frame. The hotel chair he settles into can barely contain him. It isn't a surprise to learn that he used to operate a forklift.

When Neeson starts to talk, his voice doesn't fit his imposing appearance. He speaks almost in a whisper -- creating a mood of intimacy and making me feel like a co-conspirator, as I lean over to catch every syllable. A broken- off toothpick dangles from his mouth, an old harmless habit, he assures me, when I express concern that he might swallow it.

I ask Neeson if he trained himself to talk softly to conserve his voice during his tenure with Dublin's famed Abbey Theatre. He still returns to the stage between films. He says no, that he's always spoken this way.

The timbre is just right for his latest role as pioneering sex researcher Alfred Kinsey, whose discoveries are credited with ushering in the sexual revolution of the 1960s. Few people can recall what Kinsey sounded like -- the only lasting image of him is his almost military-style haircut and trademark bow tie, which Neeson replicates in "Kinsey."

But to get people to disclose intensely personal information about their sexual behavior, such as how often they masturbate, you wouldn't want to holler the questions at them.

Bill Condon, the Oscar-winning screenwriter of "Gods and Monsters" who directed and wrote "Kinsey," confirms that Neeson's gentle voice and manner jibe with Kinsey's. The sexual pioneer has been rediscovered almost 50 years after his death.

A biography, "Kinsey: Sex the Measure of All Things," has just been reissued, and there's a thinly veiled portrayal of him and his research team - - known to engage in wife swapping and homosexual relations with one another -- in T.C. Boyle's new novel, "The Inner Circle."

"You know Kinsey had this great empathy," Condon says. "He would be sitting here with you, and you would feel incredibly comfortable talking about your sex life, probably telling things that you haven't told those people you've made love to. Liam has this incredible softness and empathy, too. "

Neeson also has displayed enormous range in his Oscar-nominated role as Oskar Schindler in "Schindler's List" and as the title Irish revolutionary in "Michael Collins." He's so good it's easy to forgive him for accepting the big bucks to play a Jedi master in "Star Wars: Episode 1 -- The Phantom Menace" and a professor in the forgettable "The Haunting," parts that somehow seem beneath him.

Condon had another reason besides talent for choosing Neeson. "He's obviously so comfortable in his own skin and obviously adores women," he says of his star, who's been romantically linked with Julia Roberts, Helen Mirren, Barbra Streisand, Jennifer Grey and Brooke Shields. "So to see him as the 26- year-old Kinsey, who was still a virgin fumbling in bed and really very bad at it, goes a little against people's expectations."

Born in 1952, Neeson came of age in the 1960s, although the '60s in his native Ballymena in Northern Ireland weren't like the '60s in San Francisco. Still, he was fortunate that his father, Barney, a custodian at a boys' primary school, and mother, Kitty, a cook at a girls' school, were relatively enlightened when it came to sex, their Irish-Catholic upbringing notwithstanding.

"Stuff got discussed when it came up," Neeson recalls. "I didn't grow up in ignorance. But I did go to school with lots of people who did not know where babies came from until quite a late age. Traditionally, in Ireland, sex outside of marriage was a big sin. But I had a very healthy upbringing."

More so, it sounds, than Kinsey's own. His father was a stern man who belonged to a Methodist church in Hoboken, N.J., but was strict enough to have been a Calvinist, according to Kinsey's biographer, Jonathan Gathorne-Hardy. Not only was Kinsey a total innocent about sex when he married his beloved Clara McMillen, nicknamed Mac, but so was she.

Neeson's scenes in bed with Laura Linney, who plays Mac, were awkward because they had to show the couple's difficulty consummating their marriage.

"The early scenes are quite painful to watch with adult audiences, because they know what's happening. It was sort of delicate, and the creaky bed we were in didn't help," says Neeson, who was put at ease because he and Linney are old colleagues. They appeared together two years ago in a Broadway production of "The Crucible." "Laura and I have good chemistry, and we don't overintellectualize stuff," he adds.

The Kinseys treated their initial problem as something that could be worked out. They discussed it with a doctor and eventually found the way to pleasure. "They discovered this great joy with each other that they never knew existed because of their own upbringing," Neeson says.

An entomologist by profession, Kinsey soon became more interested in the mating habits of humans than insects, leading to his landmark studies on male and female sexuality done in the 1940s and '50s. By simply asking the right questions, he and his team discovered that homosexuality and lesbianism were far more prevalent than had been assumed and that most men and many women masturbated. The latter finding was particularly shocking at the time.

Neeson dipped into Kinsey's reports every now and then during production. "They're tough going, especially all the charts and graphs. But occasionally, I think, Kinsey was actually a really good writer, especially on the female report. He's got some lovely paragraphs where he's talking about the difference between the sexes -- quite flowery, not at all dry and staid."

To Neeson, the greatest contribution of the man he portrays was to show that "we're all a part of the same species and have the same thoughts and fears and attitudes. He helped thousands of people and helped change or modulate laws so they weren't as harsh, especially when it came to sex between consenting adults outside marriage."

Those in Kinsey's inner circle used themselves as guinea pigs for their studies. They photographed and filmed themselves in sexual acts to see what muscle groups were involved and measure perspiration and heart rates. "It was done in a very crude way, with stopwatches," says Neeson, who hasn't seen the original photos or footage. "They're locked up in a safe somewhere."

As the movie accurately depicts, Kinsey's wife would come in during breaks with trays of sandwiches and pots of tea. "Everybody stopped and had their tea and sandwiches, and then would go back to work," Neeson says.

The onetime ladies' man has been married for 10 years to Natasha Richardson, the mother of his two sons and the daughter of Vanessa Redgrave, who, he says, is a very involved grandmother. "She's great at playing with the boys."

It isn't yet apparent if his children have inherited the acting gene. "I would not be disappointed if they decided to be doctors or bankers," says Neeson, who made his stage debut in 1976 and is all too familiar with the ups and downs of his profession.

I wondered if while shooting "Kinsey," he'd tell his wife, "My God, you wouldn't believe what happened on the set today."

Neeson laughed, quietly of course.

"To a certain extent. On a film like this with a limited budget, your feet never touch the ground. Every night there was stuff to learn. But I slept well at nights, I can tell you that."